This invention relates to current sensors for measuring current in a current carrying conductor. More particularly, this invention relates to a current sensor which may be installed in operating position around a current carrying conductor of any cross-sectional configuration, and is particularly well suited for such installation after the current carrying conductor is installed in place.
It is known to detect and measure the current flowing in a conductor by disposing the conductor through a current transformer to pick up the magnetic flux generated by the current in the conductor and with the appropriate circuitry and indicating instruments, relate that flux to a measurement of the current flowing in the conductor. Current transformers are generally large, heavy devices having the opening for receiving the conductor defined by a continuous wall, thereby necessitating that the conductor be fed through the current transformer opening. Current transformers do exist wherein the wall defining the opening for the conductor has a gate which may be opened to permit the conductor to be laid into the opening and the gate subsequently reclosed. However, such gates require precision construction and it is necessary to recalibrate the current transformer each time the gate is opened and reclosed. In many applications, such as in aircraft, the large size and heavy weight of current transformers renders them impractical and undesirable. The aforementioned disadvantages for installation of current transformers to conductors which are already in place further renders them impractical for use in aircraft.
Another disadvantage of current transformers is that the opening for the conductor is usually a specifically defined configuration for the particular conductor. Accordingly, a specific current transformer must be designed and configured for each cross-sectional shape of conductor to which it is to be applied.